Some users have reported instances in which multiple context menu entries
appeared for MediaMonkey 3.1.
e.g. right-click on an MP3 file > Open With > MediaMonkey - Audio Library

Some users have found the following tool to be helpful for solving this:
http://defaultprogramseditor.com/

This can also be solved by manually editing the registry key for the associated file type.
e.g. open the following in regedit:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.mp3\OpenWithList

Then delete all but the first MediaMonkey.exe key and any MediaMonkey (non-skinned).exe keys.
This needs to be done for all users/filetypes, so the best approach is to search the registry for
MediaMonkey.exe and delete redundant entries, pressing F3 to repeat until none found.